As shown in FIG. 3, an image forming long base member 1 used for production of printed circuit or the like has the structure comprising a long substrate 2 on the surface of which an image is formed and an image forming material 5 comprising a transparent support 3 having adhered thereon a photopolymerizable composition layer 4, the photopolymerizable composition layer 4 being in contact with the long substrate 2.
Conventionally, the exposure and development methods for such a long base member 1 as described above include the following two methods. One method comprises cutting a long base member into short base members in accordance with the size of original films to be exposed by ultraviolet rays; closely attaching individual one of the original films onto individual one of the short base member and exposing with ultraviolet rays; heating the exposed short base member if necessary; and peeling a transparent support from the short base member to thereby form a resist film having a shape of the image of the original on a substrate of the short base member. Other method comprises closely attaching an original film onto a part of a long base member in its non-cut state; exposing the long base member with ultraviolet rays; repeating the above steps to expose the long base member over its length; cutting the exposed long base member into short base members in accordance with patterns; and peeling a transparent support from each of the short base member to form a resist film having a shape of a desired image on a substrate of the short base member.
The method described above in which a long base member is cut into short pieces to be subjected to exposure development treatment has the problems that the number of working steps are increased, automatic operation is difficult, and defective products are generated in the working steps due to dust, foreign matters, hit marks, or the like, caused in the cutting step.
In order to overcome the above problems due to the short size cutting, an image forming method that after ultraviolet exposure has been conducted on a long base member in the long size state, a transparent support is peeled in the long size state from the long base member to form an image-shaped long resist film is proposed.
In the case where a long base member is exposed and developed in the long size state, however, it is difficult to continuously process the long base member by an exposure device and a development device, because the exposure device operates intermittently while the development device operates continuously. Further, the long base member must be handled one roll by one roll in the case where the long base material is processed in the long size state, resulting in unavoidable loss of production time.
Especially, in the case of an image forming material which is developed using a solvent or an alkali aqueous solution, the image forming material must be allowed to stand until the material is subjected to development after imagewise exposure, so that it is more difficult to conduct the exposure and development processing continuously. Accordingly, an improvement in that a long base member can be exposed and developed continuously has been demanded.